scholarly journals Wear Resistance of Ti–6Al–4V Alloy Ball Heads for Use in Implants

2021 ◽  
Vol 12 (4) ◽  
pp. 65
Author(s):  
Svetlana Skvortsova ◽  
Aleksei Orlov ◽  
Georgii Valyano ◽  
Victor Spektor ◽  
Natalia Mamontova

The effect of thermohydrogen treatment and vacuum ion–plasma nitriding on the determination of the volume and surface structure of ball heads made of Ti–6Al–4V alloy was studied. It was found that the submicrocrystalline structure formed in the head during thermohydrogen treatment makes it possible to achieve hardness values of 39–41 units HRC and a surface roughness of 0.02 μm. It was shown that the creation of a modified layer consisting of ε (TiN) and δ (Ti2N) titanium nitrides on the surface of a ball head and the solid interstitial solution of nitrogen in α-titanium makes it possible to completely eliminate material wear when testing for friction on ultra-high-molecular-weight polyethylene. The equivalent analysis was also conducted with a ball head that had been implanted in a human body for 12 years. It was found that the change in the color of the head, from slightly golden after nitriding to metallic, is due to the formation of an oxynitride nanoscale layer on the surface. It was shown that in contrast with films made of titanium oxide, the film developed in this study has high wear resistance.

Author(s):  
Jan Sucha´nek ◽  
Peter Jurcˇi

Thin ceramic coatings deposited on the surface of tools and machine parts by PVD methods improve considerably their tribological properties. However these hard brittle coatings can be damaged rapidly if plastic deformation initiates in the substrate near the coating-substrate interface when subject to a relatively high load. The logical way how to treat such problems is improvement of the mechanical characteristics of subsurface layers by heat treatment or thermo-chemical treatment such as plasma nitriding. The typical duplex process involves plasma nitriding and PVD coating treatment of steels. Thickness of the nitride layers depends on the activity of nitrogen in the plasma, process temperature and time. The type and thickness of nitrides can influence considerably the quality of the deposited PVD coatings and their adhesion to a nitrided substrate. High-speed steels and Cr-V ledeburitic steels were plasma nitrided and duplex-coated (pulse plasma nitriding + PVD TiN or CrN coating) at various combinations of processing parameters. The wear resistance of the non-nitrided, PVD coated and duplex-coated steel surface was examined by ring-on-plate and plate-on-plate tribological testers. The effect of subsequent PVD–coating performed on plasma nitrided specimens can be considered as very positive when the specimens were severe loaded. The tested duplex treated low-alloy steel 31CrMoV9 was pulse plasma nitrided and then coated by different PVD coatings (TiN, CrN, TiAlN and (CrN-TiN)x3). The results of tribological tests (ring-on-plate tribometer) confirmed the high wear resistance of duplex treated steels.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 323 ◽  
Author(s):  
Muzamil Hussain ◽  
Rizwan Ali Naqvi ◽  
Naseem Abbas ◽  
Shahzad Masood Khan ◽  
Saad Nawaz ◽  
...  

Ultra-High Molecular Weight Polyethylene (UHMWPE) is used in biomedical applications due to its high wear-resistance, ductility, and biocompatibility. A great deal of research in recent decades has focused on further improving its mechanical and tribological performances in order to provide durable implants in patients. Several methods, including irradiation, surface modifications, and reinforcements have been employed to improve the tribological and mechanical performance of UHMWPE. The effect of these modifications on tribological and mechanical performance was discussed in this review.


Author(s):  
Volodymyr Kropivny ◽  
◽  
Mykola Sviren ◽  
Olexandr Kuzyk ◽  
Volodymyr Amosov ◽  
...  

The purpose of this study is to improve the technology of manufacturing spherical disk working bodies of tillage machines to increase their wear resistance and strength. The world's leading manufacturers achieve high wear resistance and strength of discs made of boron-containing steels both in their chemical composition and the choice of rational heat treatment technology. Experimental studies of 30MnB5 steel parts revealed that heating for 15 minutes to a temperature of 850°C and quenching in water was sufficient to achieve maximum hardness values. To prevent hardness reduction and to ensure the necessary elasticity and viscosity of the discs, it is recommended to temper at a temperature of 180°C and combine with heat before painting with powder paint. The application of cutting blanks with cutting of depressions along the outer contour of the disk and internal holes on the laser machine, as well as the formation of the finished shape of parts in the process of hot stamping and subsequent heat treatment in quenching dies. 1. The market of disk working bodies of tillage and sowing machines is studied, technological processes of manufacturing of which it is expedient to improve. 2. Theoretical and experimental study of the structure, structure and material properties of samples of spherical disks of imported agricultural machinery. The choice of 30MnB5 pine steel for their production is substantiated. 3. The improved technological process of manufacturing spherical disks is developed. It is recommended to form them by hot stamping in cold dies and intensive hardening in a water bath. 4. The project development of the section of production of disk working bodies of tillage and sowing equipment is carried out.


2020 ◽  
Vol 30 (5-6) ◽  
pp. 195-202
Author(s):  
Vincent C. Ezechukwu ◽  
Chukwuemeka C. Nwobi-Okoye ◽  
Philip N. Atanmo ◽  
Victor S. Aigbodion

The numerical approach for the study of wear performance of breadfruit seed shell ash particles (BFSAp) and Sodium hydroxide (OH)/silane (APS)functionalized Momordica angustisepala fiber (MAf)/epoxy hybrid composites were investigated. The MAf fibers were treated with an OH-APS solution. Hardness values, wear rate and wear mechanism of the samples were determined. A 65.82% improvement in wear resistance was obtained at the load of 30N of 30wt%MAf-20wt%BFSAp composite. The wear rate and wear damage followed in this order: epoxy(matrix)˂epoxy/30wt%MAf-20wt%BFSAp˂epoxy/OH-APS treated 30wt%MAf-20wt%BFSAp composites. The wear mechanism observed in this work is a combination of abrasive and adhesive wear. High wear resistance was obtained in epoxy/OH-APS treated 30wt%MAf-20wt%BFSAp composites.


Alloy Digest ◽  
2020 ◽  
Vol 69 (10) ◽  

Abstract Dura-Bar 100-70-03 is a pearlitic ductile iron that is used for continuous cast products. It has the best wear resistance of the ascast ductile irons and is used in applications requiring high strength and high wear resistance. This grade is normally used as an alternative to quenched and tempered steels that have hardness values less than 302 HBW. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and compressive strength. It also includes information on heat treating and machining. Filing Code: CI-74. Producer or source: Charter Dura-Bar, Inc.


Author(s):  
S. N. Danilova ◽  
A. A. Dyakonov ◽  
A. P. Vasiliev ◽  
Y. S. Gerasimova ◽  
A. A. Okhlopkova ◽  
...  

The paper studies tribotechnical properties, hardness and density of composites based on ultra-high molecular weight polyethylene (UHMWPE) filled with sulfur, diphenylguanidine (DFG) and 2-mercaptobenzothiazole (MBT) and their mixtures. It has been established that the introduction of selected fillers has practically no effect on hardness and density of the composites, but leads to a significant (by 2–3 times) increase in the wear resistance of materials. Using electron microscopy, it has been established that secondary structures are formed in composites containing MBT that protect the surface layer of the material from wear. Using IR spectroscopy, it was established that tribochemical reactions occur during the wear of composites with the formation of hydroxyl and carbonyl groups. The developed materials UHMWPE / MBT and UHMWPE / FGD / MBT have high wear resistance and can be used as materials for tribological purposes.


2010 ◽  
Vol 29-32 ◽  
pp. 624-629
Author(s):  
Min Chen ◽  
W.S. Cheng ◽  
Zu Xin Zhao ◽  
X.B. Huang

The major solving ways for the material wear are surface modification and lubrication. However, the application of only one solution can not achieve desirable effect. Ni–W–P alloy coating has high hardness and high wear resistance, and is an effect way of surface modification on the 45 steel. In the friction process, the nano ceramic lubricating additives deposited on the friction surface of Ni-W-P alloy coating so as to form a protective lubricating film, therefore realizing in-situ repair on the friction surface during operation. The nano ceramic particles achieve the antiwear and friction reducing effects by the micro polishing effect, the filling and repairing effects, ball bearing effect, multiphase microcrystal effect. Experiment results confirm that Ni-W-P alloy coating and nano ceramic lubricating additive have excellent synergistic effect, and form double protection for the metal substrate, e.g., the wear resistance of Ni-W-P alloy coating (with heat treatment and the oil with nano ceramic additives) has increased hundreds times than 45 steel as the metal substrate with basic oil, zero wear is achieved,which break through the bottleneck of previous separate research of the above-mentioned the two.


2019 ◽  
Vol 27 (04) ◽  
pp. 1950131
Author(s):  
HAKAN AYDIN ◽  
FURKAN BOSTANCI

Refuse-derived fuel (RDF) is a kind of renewable energy source to produce energy for replacement of fossil fuels. Aggressive working conditions in RDF facilities cause the shredder blades to wear out quickly. So, the purpose of this paper was to study the effect of plasma-nitriding process on wear resistance of shredder blades made of AISI D2 tool steel in the service condition of RDF facility. Shredder blades were commercially available from two different suppliers (A and B suppliers). These hardened shredder blades were plasma-nitrided in the mixed nitrogen and hydrogen atmosphere at a volume ratio of 3:1 at 450∘C for 12, 18 and 24[Formula: see text]h at a total pressure of 250 Pa. Characterisation of plasma-nitrided layers on the shredder blades was carried out by means of microstructure and microhardness measurements. Wear tests of plasma-nitrided shredder blades were performed under actual working conditions in the RDF facility. Wear analysis of these shredder blades was conducted using three-dimensional (3D) optical measuring instrument GOM ATOS II. The compositional difference of the shredder blades provided by A and B suppliers played an important role on the nitrided layer. The case depth of A-blades significantly increased with increasing plasma-nitriding time. However, the case depth of B-blades was fairly lower at the same nitriding time and only slightly increased with increasing plasma-nitriding time. Plasma-nitriding process significantly improved the surface hardness of the shredder blades. Maximum surface hardness values were achieved at nitriding time of 18 h for both blades. In this case, this increase in surface hardness values was above 100%. At nitriding time of 24[Formula: see text]h, the maximum surface hardness of A-blades significantly decreased, whereas this decrease in surface hardness of B-blades was the negligible value. The wear test results showed that plasma-nitriding process significatly decreased the wear of shredder blades; 18 h nitriding for A-blades and 24[Formula: see text]h nitriding for B-blades had better wear-reducing ability in the service condition of RDF facility. In these cases, the decreases in the total volume wear loss for A- and B-blades were 53% and 60%, respectively.


2009 ◽  
Vol 83-86 ◽  
pp. 489-496 ◽  
Author(s):  
A. Triwiyanto ◽  
S. Mridha ◽  
E. Haruman

This paper describes the results of four thermochemical surface treatments of austenitic stainless steels carried out at 450oC in a fluidised bed furnace and they are nitriding, carburizing and the newly developed hybrid process involving the simultaneous and sequential incorporation of nitrogen and carbon to form a dual layer structure in order to achieve much enhanced surface hardness and wear resistance without compromising the corrosion resistance of the steel. In all these treatments there formed alloyed layers with a common feature of being precipitation-free and supersaturated with nitrogen, or carbon or both in the austenite lattice which is known as S Phase or expanded austenite. However the layer thickness was not uniform in any of these treatments and an effective layer was produced after 8h treatment duration. The nitriding treatment produced thicker and harder layer compared to other treatments; the maximum hardness was over 1500 Hv for nitriding and the minimum hardness of 500 Hv for carburizing treatment. The nitriding treatment sample gave high wear resistance which corresponded to high hardness values.


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